Hi,

I'm new on this forum. I'm also french and hope you will understand my english.

I've read a lot of topics here and I think I'm in the good place to tell you about my problem!

I've found a Mac 128k upgraded to a 512k but it doesn't work.

Here's some pictures :

https://lh6.googleusercontent.com/_UAbxSXFQB0s/TcaNxFGfNlI/AAAAAAAAASk/gbX6GB2HuAQ/s800/Sad1.JPG

https://lh4.googleusercontent.com/-Ed1SV0k7Ajo/TcaNxOApj9I/AAAAAAAAASg/fdlARnykGkI/s800/Upgrade%252520512k.JPG

Some lines are missing on the error code, and the small lines - dashes under the code move.

It makes a sound at start up so I suppose the CPU is ok.

I've tried to :

-exchange the ROMs with a 512k, ROMs are fine.

-change the RAM, (take away from a working PC 5150 motherboard)

-Use 2 different power units.

-jump the motherboard to put it on 128k (I've found the tip here),

-clean the motherboard.

But I still have the same 020400 error which tells me that the G7 RAM chip is not ok.

I know the motherboard was working a while ago and stoped working progressively (after 2 or 3 start up).

I suspect a bad capacitor but not sure at all.

I'd like to have your opinion before take the soldering station out!!

Thanks for your help.